This invention relates to a cutter attached to a dispensing container for a sheet material such as synthetic resin film, aluminum foil, wax paper, or glassine and used for cutting a necessary length of the sheet material drawn out of the dispensing container and to a dispensing container provided with the cutter. More particularly, this invention relates to a cutter for cutting the sheet material by dint of a coarse surface such as of a sandpaper which has no possibility of inflicting any injury upon the user's finger and to a dispensing container provided with this cutter.
A cutter for a dispensing container which uses a coarse file-like surface as a blade for cutting the sheet material is disclosed in the specification of U.S. Pat. No. 4,465,215. This cutter is produced by forming a file-like coarse surface on one side of a substrate. In the U.S. patent specification mentioned above, there is a statement to the effect that the file-like coarse surface is obtained by applying an adhesive agent containing abrasive granules on one side of the substrate or by applying an adhesive agent on one side of the substrate and subsequently sprinkling abrasive granules on the applied adhesive layer.
The cutter using a file-like coarse surface as its cutting blade cuts a given sheet material by first inserting a slit at one end of the sheet material by the pressure exerted thereon against a fine, sharp corner of the cutting blade and causing the slit to propagate in the sheet material throughout the entire width thereof. When this cutter is to be attached to a dispensing container, the convenience of the cutter for cutting the sheet material is improved by folding the cutter and fastening the folded cutter to the dispensing container in such a manner as to cover one corner of the dispensing container in the direction in which the sheet material is drawn out of the dispensing container thereby allowing the part of the sheet material selected for cutting to be pressed and rubbed against the cutter as disclosed in the aforementioned U.S. patent specification. If the position of attachment of this cutter deviates more or less, the cutter fulfils its function effectively so long as it avoids departing completely from the apex of the corner of dispensing container. Thus, the method described above has an advantage of facilitating the work of attachment of the cutter to the dispensing container.
When a rigid adhesive agent of the type which is rigidified by being cured through a chemical reaction or desiccation is used for fast adhesion of abrasive granules to a substrate, there ensues a disadvantage that the layer of the adhesive agent sustains a crack and sheds the abrasive granules from the cracked portion when the cutter is folded. This separation of abrasive granules results in a degradation of the sharpness of the cutter. Moreover, since the sheet material held in the dispensing container is intended more often than not to wrap foodstuffs, the separation of abrasive granules can cause an impression of filthiness on the mind of the user.
There is an adhesive agent of the type which retains flexibility even after it is cured through a chemical reaction or desiccation. Any cutter which has abrasive granules attached fast to a substrate with such a flexible adhesive agent has never been proposed in the art. This situation may be logically explained by a supposition that since sandpapers of the general run invariably use the aforementioned rigid adhesive agent for ensuring fast adhesion of abrasive granules, a concept that no ample adhesion of abrasive granules is obtained by the use of a flexible adhesive agent has been generally accepted.
To preclude the unwanted separation of abrasive granules, the desirability of having part of the abrasive granules driven into the web of the substrate is disclosed in U.S. Pat. No. 4,465,215. It is, however, extremely difficult from the technical point of view to have minute abrasive granules driven into the substrate in such a manner that their upper ends are exposed from the surface of the substrate.
In the specification of U.S. Pat. No. 4,005,809, an idea of preparing a cutter by attaching abrasive granules to a strip through the medium of an adhesive agent and fastening this strip to a dispensing container is disclosed. Further in the specification of British Pat. No. 1,483,620, an idea of directly depositing abrasive granules in a narrow strip on a dispensing container with an adhesive agent and using the produced strip of abrasive granules as a cutter is disclosed.
These two patents merely teach the formation of a file-like coarse surface by a procedure which comprises applying an adhesive agent on a substrate and sprinkling abrasive granules on the formed layer of adhesive agent thereby firmly fixing the abrasive granules therein. They have absolutely no disclosure as to the kind of adhesive agent to be used for fast adhesion of abrasive granules.